Feeding device of an electric clockwork



' Sept. 15, 1970 FEEDING DEVICE OF AN ELECTRIC 'YCLOCKWORK Filed June 4, 1968 INVENTOR. JEAN-MARCEL STAMPFLI ATTORNEY.

.KIEIAN-MIARCEL STAMPFLI 3,528,238 2 United States Patent 3,528,238 FEEDING DEVICE OF AN ELECTRIC CLOCKWORK Jean-Marcel Stampfli, Le Landeron, Switzerland, as-

signor to Fabrique dHorlogerie de Fontainemelon, Succursale du Landeron S.A., Le Landeron, Canton of Neuchate, Switzerland, a firm of Switzerland Filed June 4, 1968, Ser. No. 734,370 Claims priority, application Sw7itzerland, June 8, 1967, 50/6 Int. Cl. G04c 3/00 US. C]. 58-23 1 Claim ABSTRACT OF THE DISCLOSURE A feeding device producing a stabilized feeding current to an electric clockwork and comprising, a pair of resistances, a condenser connected in parallel with one of the resistances to permit the alternate pulses coming from the clockwork to close themselves on a low impedance circuit constituted by the condenser and by a source of direct feeding current while producing the self-starting of the clockwork at the time of switching on the clockwork as the condenser operates substantially as a short circuit with respect to the resistance with which it is connected in parallel.

The present invention relates to a feeding device of an electric clockwork for providing a stabilized feeding current.

The feeding devices of an electric clockwork must present the following properties so that the clockwork will operate satisfactorily.

It must:

(1) Supply direct current that is well stabilized.

(2) Present a very weak internal resistance to the alternate short pulses emanating from the clockwork. (3) Permit the self-starting of the electric clockwork by means of the sudden appearing of the feeding current to the input of the clockwork when put under tension.

The purpose of the present invention is to provide a feeding device of an electric clockwork which provides these three properties.

This feeding device is characterized by the fact that it comprises a condenser connected in parallel with one of a pair of resistances, this condenser allowing the alternate pulses coming from the clockwork to be detected in the low impedance circuit constituted by the condenser and by a source of direct feeding current, while providing self-starting of the clockwork when it is put under tension owing to the fact that the condenser operates substanially as a short circuit with respect to the resistance with which it is connected in parallel.

The drawing is an electrical diagram showing by way of example, one embodiment of the invention.

Portion I represents the feeding device and portion II represents the circuit of an electric clockwork, all for facilitating an understanding of the operation of the feeding device.

The feeding device comprises a source of feeding current 1, having two terminals designated by A and B, the internal resistance of which is relatively weak with respect to the resistance of the electric clockwork. In case the source of current has too high an internal resistance, same can be remedied by the addition of a condenser connected in parallel therewith.

The stabilization of the current is produced by a linear resistance R and by a non-linear resistance R constituted by two diodes directly connected. Non-linear resistance R could also be constituted by a resistance VDR, by a Zener diode or by any non-linear means. The suitable choice of the resistances R and R allows maintenance to between points C and B of the circuit of a stable current of a desired value. Thus the tension between the terminals A and B of the source of current can vary to a large extent without the tension between points C and B being submitted to any substantial change, all so that the condition of a well stabilized supply current is met.

A switch 1, connected between terminals A and resistance R allows the on and off switching of the feeding device.

A condenser C is connected in parallel with resistance R The electric clockwork comprises a driving coil B,,,, a pickup coil B of a conventional horological vibratory or oscillator element carry permanent magnet means which interact with coils B and B a transistor T, a capacity C connected in series with pickup coil B and a base 2 of transistor T, and a constant time, constituted by a capacity C and by a resistance R mounted in parallel, connected between base 2 and a collector 3 of transistor T.

Condenser C of the feeding device serves three func tions:

(1) It bypasses resistance R permit the signal induced in pickup coil B to circulate in the circuit constituted by condenser C base 2 and an emitter 4- of transistor T, the feeding source U, the switch 1', and condenser C with backway to B all without any substantial weakening, so as to produce a feeding. of the transistor.

That is to say, the signal induced in pickup coil B must be able to pass in a circuit of low impedance, a condition necessary for successful operation of the clock work and a provision of the second of the above-mentioned properties.

(2) It levels the tension at the outputs of resistance R in the manner of a filter. Its etfect is especially useful when current shocks are produced, due to the opening of the transistor, and circulate in the circuit constituted by driving coil B collector 3 and emitter 4 of transsistor T, feeding source U, switch 1' and condenser C This also serves to provide the second of the abovementioned properties.

(3) As the clockwork is placed under tension, by means of switch 1', condenser C is unloaded so as to provide a short circuit, at switching on, and thus a sufficient pulse of current to the clockwork to produce the self-starting of the latter and thus to provide the third of the above-mentioned properties.

It is to be noted that, when the force of current U is not connected, that is to say when switch 1 is open, condenser C unloads itself into resistance R so that it is unloaded at the next switching on.

In the embodiment shown, the several elements of the circuit can have, for instance, the following values:

Source of current U6 to 18 v. Resistance R,] to 2K9 Resistance R KS2 Capacity C 10 ,uf.

Capacity C 20 ,uf.

Capacity C -O.1 at.

It is also to be noted that, in the usual stabilisers of current, condenser C is in parallel with non-linear resistance R This arrangement has the drawback of not permitting self-starting, due to the fact that condenser C would then short-circuit resistance R The tension to the inputs of the clockwork could thus, at the time of switching on increase only slowly, as condenser C is loaded through resistance R with the result that it would n 3 not produce the current shocks necessary for the selfstarting of the clockwork.

What I claim is:

1. In combination with an electric clockwork including a driving coil, a pickup coil, a transistor, a capacity in series with the pickup coil and a base of the transistor, a capacity and resistance in parallel and connected between the base and a collector of the transistor and a feeding device for providing a stabilized feeding current to the clockwork whenein said comprises:

a source of direct feeding current,

a switch for the feeding of the feeding current,

a linear resistance and a non-linear resistance for stabilizing the feeding current,

a condenser connected in parallel with the linear re sistance for bypassing the linear resistance upon a switch on of the feeding current and providing a pulse to the clockwork adequate for the self-starting of the clockwork wherein said non-linear resistance is connected between said terminals of said source, said condenser is located between one of said terminals of said source and said non-linear resistance and said feeding device is connected across both the input and the output of said transistora References Cited UNITED STATES PATENTS 3,293,568 12/1966 Ganter et a1 5823 RICHARD B. WILKINSON, Primary Examiner E. C. SIMMONS, Assistant Examiner U. S. Cl. X.R. 318-430 

